Field of the Invention
The invention relates to medical devices and methods of medical treatment. The invention relates to a medical device and method of treatment used to create an aperture in the interatrial septum of a heart.
Background Art
There are some medical conditions that are treated by creating an opening between body chambers in order to create a connection between the chambers. The heart has an interatrial septum or wall that separates the left atrium and the right atrium. In certain heart failure patients (e.g., heart failure with preserved ejection fraction (diastolic dysfunction)) there is a need to allow blood flow from the left atrium to the right atrium to reduce left atrial pressure. Likewise, certain other heart diseases and conditions, such as congenital heart diseases and pulmonary hypertensions may require a similar treatment. Implanting a stent in the interatrial septum has been used as a treatment for elevated pressure in one atrium by allowing blood to flow through the opening to the other atrium to reduce blood pressure. A heart surgeon implants the stents in certain predetermined sizes in an effort to control the amount of blood flow between the atria.
One procedure uses a balloon to create a hole in the septum. However, it has been found that a hole created in this manner may not stay open and after a period of time may spontaneously close. This renders this particular therapeutic solution temporary.
A few other devices have been proposed in order to overcome the temporary solution of using a balloon. One device is to use a stent to keep the hole open. Another device uses a valve inserted into the septum that keeps the hole open and also assists in controlling blood flow. Significant drawbacks to these devices are that they are permanent implants that can promote thrombosis and are potentially subject to infection.
Another major drawback of these devices is that they are not capable of removing a segment of the septum. The benefit of removing a segment of the septum is that hole will be less likely to close spontaneously. The stents may also become spontaneously dislodged and embolize and cause cardiac damage or blockage of blood flow.
Therefore, it would be desirable to have a medical device that is capable of creating an incision or an opening in the interatrial septum of the heart to alleviate pressure between chambers in the heart that does not suffer from the limitations of prior devices or procedures. It would be advantageous to have a catheter that can create various slits, openings, or apertures in the interatrial septum in a predetermined orientation. It would also be advantageous to have a catheter that may be easily manipulated to remove a section of the interatrial septum to form a permanent hole that is less likely to spontaneously close.